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Date:   Wed, 7 Sep 2022 13:43:20 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     "Sun, Jiebin" <jiebin.sun@intel.com>
Cc:     Tim Chen <tim.c.chen@linux.intel.com>,
        Shakeel Butt <shakeelb@google.com>, vasily.averin@linux.dev,
        Dennis Zhou <dennis@kernel.org>, Tejun Heo <tj@kernel.org>,
        Christoph Lameter <cl@linux.com>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Alexey Gladkov <legion@kernel.org>,
        Manfred Spraul <manfred@colorfullife.com>,
        alexander.mikhalitsyn@virtuozzo.com, Linux MM <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>,
        "Chen, Tim C" <tim.c.chen@intel.com>,
        Feng Tang <feng.tang@intel.com>,
        Huang Ying <ying.huang@intel.com>, tianyou.li@intel.com,
        wangyang.guo@intel.com
Subject: Re: [PATCH] ipc/msg.c: mitigate the lock contention with percpu
 counter
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On Wed, 7 Sep 2022 17:39:47 +0800 "Sun, Jiebin" <jiebin.sun@intel.com> wrote:

> I have sent out the patch v4 which use percpu_counter_add_batch. If we use
> a tuned large batch size (1024),

Oh.  Why not simply use a batch size of INT_MAX?

> the performance gain is 3.17x (patch v4)
> vs 3.38x (patch v3) previously in stress-ng -- message. It still has
> significant performance improvement and also good balance between
> performance gain and overflow issue.